1. Field of the Invention
This application is related to my copending application, U.S. Ser. No. 134,750 filed on even date herewith).
The present invention relates generally to slide fasteners, and more particularly to a slide fastener slider having a detachable pull tab.
2. Prior Art
Japanese Utility Model Laid-open Publication No. 61-72209 discloses a slide fastener slider having a detachable pull tab. The disclosed slider includes an arch-shaped lug projecting from the top surface of an upper wing and terminating in a rear free end spaced from the top surface of the upper wing by a gap greater than the diameter of a spindle of the pull tab, and a closure member slidably mounted in the upper wing for opening and closing the gap to detachably connect the pull tab to a body of the slider.
The known slider of the foregoing construction, however, is not fully satisfactory in that the cross-sectional area of the lug's rear free end A is considerably smaller than the area of an opening B in the pull tab C and hence the pull tab C is freely oscillatable about the spindle D in the lateral directions indicated by the arrows E, F shown in FIG. 9. If the pull tab C were laterally displaced during the sewing operation of a slide fastener having such slider G to an article such as a garment fabric or a bag, the displaced pull tab C would interfere with a sewing needle, thereby lowering the sewing efficiency and sometimes damaging or otherwise breaking the sewing needle.
Such lateral displacent or oscillation of the pull tab C will not occur when the lug's rear free end A and the closure member H are elongated in the longitudinal direction of the slider G to such an extent that the opening B in the pull tab C is substantially filled with the elongated rear free end A and the elongated closure member H, as shown in FIG. 10. With this elongation of the rear free end A, the stroke I of the closure member H must be long enough to open and close the gap between the elongated rear free end A and the upper wing of the slider body J. In practice, however, the stroke I of the closure member H is restricted to a small extent so as not to lower the mechanical strength of the slider body J.